链表中倒数第K个节点

class Solution {
public:
    ListNode* FindKthToTail(ListNode* pListHead, unsigned int k) {
        if(pListHead == NULL || pListHead->next == NULL)
            return pListHead;
        
        ListNode* cur = pListHead;
        int count = 0;
        while(cur){
            count++;
            cur = cur->next;
        }
        if(k > count)
        {
            return nullptr;
        }
        int tmp = count-k;
        for(int i = 0; i < tmp; i++)
        {
            pListHead = pListHead->next;
        }
        return pListHead;
    }
};